It's like suggesting gmail would fail because they have spam filters. People actually want moderation. As long as it's mostly good or at least consistent, I expect Meta to find success. I also expect a wide variety of more lax/niche aggregators to also find success.

Meta's moat will be that they will be the largest home domain. They'll have the most user data and they'll have a secured user base even if the fediverse collapses.